The invention relates to a device and a method for controlled braking of a vehicle having a hydrostatic drive mechanism.
DE 196 38 421 A1 discloses a traction control system whereof the use is provided as a control of a hydraulically driven vehicle having a front and a rear drive unit. This traction control system has, for each drive unit, a hydraulic motor connected to the latter and having variable displacement, the hydraulic motors being connected in parallel to a pump. Provided in the traction control system is a central control system which detects parameters such as the speed, the direction of movement and the inclination in relation to the surface of the ground and processes them further such that they are used to activate the hydraulic motors of the front and rear drive units, such that when slip occurs at an axle, the hydraulic motor of the axle concerned is adjusted accordingly.
A disadvantage of the traction control system described in DE 196 38 421 A1 consists in the fact that even though the throughput through a hydraulic motor may change the quantity conveyed by the pump remains constant. This means that a reduction in the throughput through the hydraulic motor may bring about an increase in pressure in the lines of the hydraulic circuit, with these lines and in particular their connection points being overloaded. An increase in the throughput, by contrast, has the effect of a drop in pressure in the lines of the hydraulic circuit, with there again being a risk of mechanical damage to the lines because of the possibility of cavitation occurring. Moreover, no account is taken of the dynamic braking behaviour.
The object of the present invention is to provide an improved method and an improved device for braking a vehicle which also takes account of the dynamics of performing braking.